Encryption takes more horsepower than sending data in the clear. It really shows up on mobile PCs transmitting large hunks of data — for example, a PowerPoint presentation — over a dial-up phone line. Firewalls and other server systems should employ hardware crypto engines. With these there are no performance issues. I expect that this functionality for mobile PCs will migrate to PC cards with crypto engines. When will this happen? Within the next 18 months.